The invention relates to a belt retractor comprising a frame, a sensor for vehicle-sensitive blocking which includes a sensor lever, a belt reel and a rocker arm coupled to the belt reel via a coupling which is adjustable between a home position in which the sensor lever is blocked and an extended position in which the sensor lever is released.
Belt retractors include a vehicle-sensitive blocking system usually provided with a sensor which generally has, as an inertia mass, a metal ball that is movably supported in a shell fixed to a housing. A sensor lever which is pivoted on a housing and is swiveled about a swivel bearing by the movement of the metal ball rests on the metal ball. When the sensor lever is swiveled in such way, the end thereof gets into the path of motion of control teeth at the periphery of a control disk arranged to be rotatable to a limited extent on the belt reel. In this way, the control disk is stopped so that relative rotation between the control disk and the belt reel will take place. Said relative rotation is exploited so as to move a blocking pawl pivoted on a frame of the belt retractor in blocking engagement with blocking teeth assigned to the belt reel.
In order to reduce the occurrence of disturbing notes by vibrations onto the vehicle during driving, for example on uneven roads, it is known from DE 10 2006 037 544 A1 to provide an additional rocker arm which is coupled to the belt reel via a friction coupling and blocks the sensor lever in the home position. The sensor lever is blocked by said rocker arm in almost all operating states of the belt retractor so that the sensor lever is reliably prevented from rattling. The sensor lever is released by the rocker arm only when the belt reel is or was rotated in the unwinding direction, i.e. in operating states such as strong deceleration during which the belt reel has to be blocked. In such belt retractors, the coupling is exposed to very high loads.